Seat fold actuator

ABSTRACT

An actuator configured to actuate a member. The actuator optionally including capabilities for storing and releasing kinetic energy. The actuator being suitable for use in any number of environments, including but not limited to facilitating seat folding operations.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.12/397,608 filed Mar. 4, 2009, which is a divisional of U.S. applicationSer. No. 11/472,203 filed Jun. 21, 2006, now U.S. Pat. No. 7,547,070 B2on Jun. 16, 2009, the disclosures of which are incorporated in theirentirety by reference herein.

TECHNICAL FIELD

The present invention relates to seat fold actuators.

BACKGROUND

Actuators and triggers are devices that cause an apparatus to operate.Latches are devices that are used to grasp or lock an object, as with acatch and a lever, or the like. An actuator may be used to release orengage a latch. Some actuators may be remotely connected to a latch toallow for operation of the latch from a distance.

Latches are used in a wide variety of applications. For example, latchesmay be provided as a part of a machine, on building doors or windows, orin vehicles. Latches that can be reset have the advantage that they canbe used repeatedly. One way to provide a latch that can be reset is toprovide an actuator that operates a motor and gear reducer to releasethe latch by forward rotation of the motor and reset the latch byreverse rotation of the motor. While this approach is effective, thecost of a motor and gear reducer may be uneconomical in manyapplications.

In some applications, it may be desirable to provide a manual actuatorand a power actuator for a latch that may be alternatively used tooperate the latch. Dual mode actuators may be provided to allow a latchto be manually operated or power operated. One problem with such dualactuation latches is that one mode of actuation may interfere with theother mode. In addition, resetting the dual mode actuator may becomplicated if both modes of actuation are not accommodated by the resetmechanism.

One exemplary application for a dual mode remotely actuated latch is avehicle seat back folding apparatus. Vehicle seat backs may be foldedover the seat base to facilitate ingress and egress. Prior art actuatorshave been developed that use a motor that drives a gear reducer in onedirection to release a latch and driven in the opposite direction toreset the actuator for reuse after the latch is engaged. Seat foldinglatches may also be specified to be manually actuated in the event thata user wishes to operate the latch manually or if power is not availablefor the power actuation system. While these types of systems have beendeveloped, the cost of the motor and gear reducer may make such systemsuneconomical.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is pointed out with particularity in the appendedclaims. However, other features of the present invention will becomemore apparent and the present invention will be best understood byreferring to the following detailed description in conjunction with theaccompany drawings in which:

FIG. 1 illustrates a vehicle seat in accordance with one non-limitingaspect of the present invention;

FIG. 2 illustrates one way of connecting a seat back to a seat base inaccordance with one non-limiting aspect of the present invention;

FIG. 3 illustrates a trigger assembly in more detail in accordance withone non-limiting aspect of the present invention;

FIG. 4 illustrates a folded over seat position in accordance with onenon-limiting aspect of the present invention;

FIG. 5 illustrates a flipped forward seat position in accordance withone non-limiting aspect of the present invention;

FIG. 6 illustrates an assembly view drawing of the trigger assembly inaccordance with one non-limiting aspect of the present invention;

FIGS. 7 a-9 b illustrate operation of the trigger assembly in accordancewith one non-limiting aspect of the present invention.

DETAILED DESCRIPTION

As required, detailed embodiments of the present invention are disclosedherein; however, it is to be understood that the disclosed embodimentsare merely exemplary of the invention that may be embodied in variousand alternative forms. The figures are not necessarily to scale; somefeatures may be exaggerated or minimized to show details of particularcomponents. Therefore, specific structural and functional detailsdisclosed herein are not to be interpreted as limiting, but merely as arepresentative basis for teaching one skilled in the art to variouslyemploy the present invention.

Referring to FIG. 1, a vehicle seat 10 is illustrated that has a seatback 12, a seat base 14, and a trigger assembly 15. An actuator 18 isillustrated as being attached to the seat base 14. However, it should beunderstood that the actuator 18 could be secured to another location onthe vehicle or seat support structure. A latch lever 20 is connected tothe actuator 18 by a Bowden cable 22, or link. The Bowden cable 22includes a sleeve 24 that encloses a wire 26 so that the wire 26 isaxially moveable relative to the sleeve.

The wire 26 connects to a trigger plate 27 such that actuation of thewire 26 in the downward direction causes the trigger plate 27 to move ina counter-clockwise direction and to over come spring biasing providedby a chaser spring 29 in an opposite, locking direction. A power platewire 31 connects a power plate 33 to the latch lever 20 such that apower plate spring 25 instigates counter-clockwise rotation of a powerplate 33 in an actuation direction in order to cause the latch lever 20to pivot in similar counter-clockwise manner about pivot 46. A resetwire 35 connects to power plate 33 and can be tensioned with rotation ofthe seat back 14 in order to facilitate resetting the power plate 33, asdescribed below in more detail.

First and second mirroring wires 37 and 39 actuate mirroring features onan opposite side of the seat 10 so as to perform mirroring operationsassociated with actuating a mirroring latch lever (not shown). Themirroring operations essentially facilitate releasing the opposite sideof the seat in a manner similar to the illustrated side of the seat, butoptionally without a second trigger assembly 15.

Referring to FIG. 2, one type of hinge mechanism is shown in greaterdetail in an exploded perspective view that shows one way of connectingthe seat back 12 to the seat base 14. It should be understood that othertypes of hinge mechanisms may be adapted to include the latch actuatorsystem of the present invention. A pair of seat base plates 36 areconnected to a seat back support bracket 38 by means of a pivot pin 40.Pivot pin 40 is received in a hole 42 that extends through the seat baseplates 36, seat back support bracket 38 and bracket 32. A spring bracket44 retains seat spring 30 and interconnects the seat spring 30 to thepivot pin 40. The latch lever 20 shown in FIG. 1 is connected to a leverpivot pin 46.

The latch lever 20 is secured to the lever pivot pin 46 which is in turnsecured to a latching follower 56. The seat back support bracket 38includes a step 58 that is engaged by the latching follower 56 when theseat is in its latched position. After the seat is unlatched, thelatching follower 56 follows an arcuate cam surface 60 on the supportbracket 38 as the support bracket 38 pivots about pivot pin 40 into aposition where a seat back 12 is folded over the seat base 14.

Referring now to FIGS. 3-4, the trigger assembly 15 is described withreference to the embodiment of the invention described above withreference to FIGS. 1 and 2. FIG. 3 is an enlarged illustration of aportion of the apparatus described with reference to FIG. 1 that iswithin the oval denoted FIG. 3 in FIG. 1. In FIG. 3, the apparatus isshown in its latched condition with the seat back support bracket 38held in a vertical, rearwardly inclined orientation and is fixedrelative to the seat base plates 36. In this position the latch lever 20is in its retained position.

A cable sleeve bracket 64 secures the sleeve 24 to seat base 14 or othersupporting structure. A handle 70 is provided at the opposite end of thelatch lever 20 from the cable sleeve bracket 64. The handle 70 isintended to be grasped directly or indirectly by a person for manuallymanipulating the latch lever 20. The latch is lifted to cause thelatching follower 56 to clear the step 58 and seat back 12 to moveforwardly with the force applied by the seat spring 30, thereby allowingthe seat back 12 to rotate to a folded over position as the latchingfollower 56 follows the arcuate cam surface 60.

While not shown, the handle 70 may be provided with an enlarged handlecover to make the handle 70 easier to grasp and to provide a finishedappearance. As shown in FIG. 3, a slack portion 72 may be provided inthe wire 39 to allow the handle 70 to be easily lifted withoutencountering resistance from the seat spring 30 mirroring element (notshow) to which the wire 39 is connected. The extent of slack is somewhatexaggerated as shown for illustrative purposes.

Referring to FIG. 4, actuation of the latch 20 is illustrated in eithera manual or power mode. In the manual mode the lever 20 may be manuallygrasped and moved from the position shown in phantom lines to theposition shown in solid lines. When the latch lever 20 is lifted, thelatching follower 56 disengages the step 58 as previously described.Alternatively, the latch may be power actuated upon triggering theactuator 18. The actuator 18 may comprise a shape memory alloy trigger,a solenoid or other actuator that is capable of exerting a tensioningforce on wire 26. In the embodiment illustrated in FIG. 4 the actuator18 exerts a pulling force on the cable that pulls the trigger plate 27in a counter-clockwise direction. This movement causes the triggerassembly 15 to move from a loaded position to a fired position whereinthe trigger plate 27 triggers the power plate 33 to pull upwardly on thewire 31, which thereby pulls upwardly on the latch lever 20 to actuatethe latch lever 20 from the retained position to the released position.

When the lever actuator 20 is rotated about the pivot pin 46 from theretained position to the released position the latching follower 56disengages the step 58 as previously described. When the latchingfollower 56 clears the step 58 the seat back support bracket 38 movesfrom the position shown in phantom lines in FIG. 4 along the curvedarrow path to the position shown in solid lines in FIG. 4. The seatspring 30 drives the seat back 12 and its associated support bracket 38into the folded over position.

Optionally, as shown in FIG. 5, the seat 10 may automatically flipforward to the illustrated stadium seat position (folded forwardposition) once the seat back 12 reaches the folded over position. A seatbase actuator system 67, or other arrangement, may be included tofacilitate such movement. The seat base actuator system 67 may include acable or other feature (not shown) connected to the seat back 12,support 38, or other feature in the system 10 such that actuation of theseat back 12 to the folded down position allows the seat base actuatorsystem 67 to then flip the seat back 12 and seat base 14 to the stadiumor flipped forward position shown in FIG. 5.

As the seat back 12 folds to or is folded up from the folded position(fold flat, flipped forward, etc.), the reset cable 35 tightens from itsslack position to rotate the power plate 33 from its released position(FIG. 4) to its loaded position (FIG. 3). This movement resets thetrigger assembly 15 such that the power plate 33 is loaded and ready totrigger rotation of the lever latch 20 in response to triggering of thetrigger plate 27. A reset mechanism 68 may be included on the seat baseactuator system 67 to facilitate tensioning the reset cable 35 or someother mechanism may be similarly employed.

FIG. 6 illustrates an assembly view drawing of the trigger assembly 15in accordance with one non-limiting aspect of the present invention. Thetrigger assembly 15 may include the trigger plate 27 on one side of areference plate 80 and the power plate 33 on an opposite of the samesuch that both plates are configured to rotate coaxially about a centralportion 82 of the reference plate 80. Each of the reference plate 80,trigger plate 27, and power plate 33 may include common apertures 86-90for receiving a ball bearing 94-98. The apertures 86-90 on each platemay be arranged relative to each other such that they cooperate tocontrol actuation of the trigger assembly 15 from the loaded to firedpositions.

A chaser spring 29 may be attached to the reference plate 80 and thetrigger plate 27 such that the chaser spring 29 causes the trigger plate27 to rotate in a clockwise direction relative to the reference plate80. A power spring 102 may be attached to the reference plate 80 and thepower plate 33 such that the power plate spring 25 causes the powerplate 33 to rotate in a counter-clockwise direction relative to thereference plate 80. As described below in more detail, thecounter-clockwise rotation of the power plate spring 25 may be used toactuate the power plate 33 and the connected latch lever 20 from theretained position (loaded position) to the released position (firedposition). Similarly, the clockwise rotation of the chaser spring 29 maybe used to return the trigger plate 27 from the fired position to theloaded position.

FIGS. 7 a-9 b illustrate the interaction of ball bearing 94 with one ofthe corresponding apertures 86 in accordance with one non-limitingaspect of the present invention. FIGS. 7 a-7 b relate to the loadedposition, FIGS. 8 a-8 b relate to the fired position, and FIGS. 9 a-9 brelated to returning from the fired to loaded position. The loadedposition includes the trigger assembly 15 storing kinetic energyassociated with a cocked or otherwise flexed power plate spring 25 suchthat the ball bearing 94 is disposed partially within the aperture 86 ofthe power plate 33 such that the power plate 33 is unable to move in thecounter-clockwise direction. The fired position relates to the releasingof the stored energy and the counter-clockwise rotation of the powerplate 33, i.e., the releasing of the power plate spring 25 to rotate thepower plate 33 and thereby actuate the latch lever 20.

From the loaded position, the fired position may be obtained withmovement of the trigger plate 27 in a counter-clockwise direction, suchas with actuation of the trigger wire 26. This movement aligns theaperture 86 of the trigger plate 27 with the corresponding aperture 86of the reference plate 80. Because the power plate 33 is under forcefrom the power plate spring 102, the power plate is urged against theball bearing 94 such that once the trigger plate 27 is aligned with thereference plate 80, the ball bearing 95 travels along an incline 106 andinto the apertures 86 of the reference plate 80 and trigger plate 27,thereby freeing the power plate 33 to move in the counter-clockwisedirection, which as described above actuates the latch lever 20 from theretained position to the released position.

From the fired position, and once tensioning on the trigger wire 26 isremoved or decreased below the force of the chaser spring 29, the chaserspring 29 forces the trigger plate in a clockwise direction such that anincline 108 on the trigger plate 27 forces the ball bearing 94 in adownward direction, once the power plate 33 is properly aligned toreceive the ball bearing 94. The power plate 33 may receive the ball 94if it is reset, i.e., returned to the positioning shown in FIG. 7 a thatpermits the ball bearing 94 to be disposed within a portion of the powerplate 33. The power plate 33 may be reset in any manner, includingtensioning or other tightening of the reset wire 35, such as by theflipping of the seat back 14 and/or seat base 12 described above.

In the illustrated embodiments, the seat backs 12 are disclosed asexamples. The seat back may be more generically referred to as a latchedmember. Other types of latched members may include a seat base, acombination of a seat base and seat back, a headrest, a flat screenvideo display, a compartment cover, a glove box door, a hood, a decklid, a seat back tilt adjustment armature, and the like. Another examplein which more than one latched member is controlled by the latch andtrigger is that of a seat back that folds over a seat base, and then thefolded over seat is tumbled forward for storage, ingress, and egress.With any of those arrangements the trigger is electrically actuated anda movement of the latched member is executed to reset the trigger.

As required, detailed embodiments of the present invention are disclosedherein; however, it is to be understood that the disclosed embodimentsare merely exemplary of the invention that may be embodied in variousand alternative forms. The present invention fully contemplates itsapplication in any number of environments, including those associatedwith U.S. patent application Ser. No. 11/278,295, filed Mar. 3, 2006,the disclosure of which is hereby incorporated in its entirety. Thefigures are not necessarily to scale, some features may be exaggeratedor minimized to show details of particular components. Therefore,specific structural and functional details disclosed herein are not tobe interpreted as limiting, but merely as a representative basis for theclaims and/or as a representative basis for teaching one skilled in theart to variously employ the present invention.

While exemplary embodiments are described above, it is not intended thatthese embodiments describe all possible forms of the invention. Rather,the words used in the specification are words of description rather thanlimitation, and it is understood that various changes may be madewithout departing from the spirit and scope of the invention.Additionally, the features of various implementing embodiments may becombined to form further embodiments of the invention.

1. An assembly operable to actuate a latch from a retained position to areleased position, the assembly comprising: a power plate operable toactuate the latch from the retained position to the released positionwith kinetic energy provided from a power spring; at least one ballbearing positioned within each of at least one aperture of the powerplate, each ball bearing being operable between a stored position and afreed position, the stored position preventing the power plate fromactuating the latch from the retained position to the released positionand the freed position freeing the power plate to actuate the latch fromthe retained position to the released position; and a trigger platehaving an aperture for each of the at least one ball bearings, thetrigger plate being moveable between a blocking position andnon-blocking position, the blocking positioning de-aligning the triggerplate apertures to the ball bearing apertures to block the ball bearingsfrom the free position and the non-blocking position aligning thetrigger plate apertures to the ball bearing apertures to allow the ballbearings to reach the free position.
 2. The assembly of claim 1 whereinthe power spring provides substantially all kinetic energy used toactuate the latch from the retained position to the released position.3. The assembly of claim 2 wherein the ball bearings retainsubstantially all of kinetic energy of the power spring when in thestored position.
 4. The assembly of claim 1 wherein the power plateapertures include an incline surface for directing movement of the ballbearings to the freed position.
 5. The assembly of claim 1 wherein thetrigger plate apertures include an incline surface for directingmovement of the ball bearings to the stored position.
 6. The assembly ofclaim 1 wherein a distance traveled by each ball bearing when movingfrom the stored position to the free position is less than half adiameter of the ball bearing.
 7. The assembly of claim 1 wherein anadditional spring applies kinetic energy to the trigger plate to forcethe ball bearings from the free position to stored position, the ballbearings retaining the kinetic force of the additional spring when inthe stored position.
 8. The assembly of claim 1 further comprising areference plate having an aperture for each of the at least one ballbearing, the apertures of the reference plate facilitating movement ofthe lease one ball bearing between the corresponding apertures of thepower plate and the trigger plate.
 9. The assembly of claim 8 wherein atleast a portion each of the at least one ball bearing remains within theapertures of the reference plate when in the stored position and thefree position.
 10. The assembly of claim 8 wherein the reference plateis gear-less.
 11. The assembly of claim 10 wherein each of the powerplate and the reference plate are gear-less.
 12. The assembly of claim 1further comprising a chaser spring operable to actuate the trigger platefrom the non-blocking position to the blocking position.
 13. Theassembly of claim 12 wherein the chaser spring actuates the triggerplate from the non-blocking position to the blocking position in adirection counter-clockwise to a direction of the power spring.
 14. Anassembly operable to actuate a latch from a retained position to areleased position, the assembly comprising: a power plate operablebetween a first position and a second position, the latch being in theretained position when the power plate is in the first position in thelatch being in the released position when the power plate is in thesecond position; a power spring operable to move the power plate fromthe first position to the second position; a reference plate adjoiningthe power play; a trigger plate operable between a blocking position anda non-blocking position, the latch being in the retained position whenthe trigger plate is in the third position in the latch being in thereleased position when the trigger plate is in the fourth position, thereference adjoining the reference plate; a chaser spring operable tomove the trigger plate from the blocking position to the non-blockingposition; and wherein the reference plate remained stationary while thepower plate moves from the first position to the second position andwhile the trigger plate moves from the blocking position to thenon-blocking position.
 15. The assembly of claim 14 further comprisingat least one ball bearing journaled within the reference plate, the atleast one ball bearing movable between corresponding apertures includedin each of the power plate and the trigger plate, the at least one ballbearing preventing movement of the power plate from the first positionto the second position when at least partially positioned within thecorresponding apertures of the power plate.
 16. The assembly of claim 15wherein the trigger plate blocks the at least one ball bearing fromexiting corresponding apertures within the power plate when in theblocking position and permits the at least one ball bearing to exitcorresponding apertures within the power plate when in the non-blockingposition, the at least one ball bearing entering corresponding apertureswithin the trigger plate when the trigger plate is in the fourthposition.
 17. The assembly of claim 14 wherein each of the power plate,the power spring, the reference plate, the trigger plate, and the chaserspring are coaxial.
 18. The assembly of claim 14 wherein a distancetraveled by each ball bearing when moving between correspondingapertures included in each of the power plate and the trigger plate isless than half a diameter of the ball bearing.
 19. An assembly operableto actuate a latch from a retained position to a released position, theassembly comprising: a power plate operable between a first position anda second position, the latch being in the retained position when thepower plate is in the first position in the latch being in the releasedposition when the power plate is in the second position; a referenceplate adjoining the power play; a trigger plate operable between ablocking position and a non-blocking position, the latch being in theretained position when the trigger plate is in the third position in thelatch being in the released position when the trigger plate is in thefourth position, the reference adjoining the reference plate; andwherein the reference plate remained stationary while the power platemoves from the first position to the second position and while thetrigger plate moves from the blocking position to the non-blockingposition.
 20. The assembly of claim 19 further comprising at least oneball bearing journaled within the reference plate, the at least one ballbearing movable between corresponding apertures included in each of thepower plate and the trigger plate, the at least one ball bearingpreventing movement of the power plate from the first position to thesecond position when at least partially positioned within thecorresponding apertures of the power plate, and wherein the triggerplate blocks the at least one ball bearing from exiting correspondingapertures within the power plate when in the blocking position andpermits the at least one ball bearing to exit corresponding apertureswithin the power plate when in the non-blocking position, the at leastone ball bearing entering corresponding apertures within the triggerplate when the trigger plate is in the fourth position.